Searching for rare coins in the ground can make you feel like a modern-day Indiana Jones. The thrill of unearthing a little slice of buried treasure can be invigorating. For today's treasure hunters, the tool of choice is the metal detector. While most hunting sites are historic buildings, parks and other populated places where valuable coins from the past may be buried, the wisest hunters look for treasures in the least likely places, such as their backyards. The key to finding rare coins buried underground is to remain persistent and always be on the lookout, because you never know what you'll dig up.
Choose a metal detector that suits your needs. The model chosen depends on how you intend to use it. You don’t need to spend thousands of dollars on the detector if it's only for a hobby. If you are serious about finding coins, more sophisticated models exist that include more sensitive electromagnetic coils and even feature LCD displays to show you exactly what you've found before you even pull out a trowel to start digging.
Sweep the detector slowly and low to the ground. Even higher-end metal detectors work better when you use good technique -- sweeping slowly, making sure your subsequent passes overlap and keeping the detector's coil, the electromagnetic element of the metal detector, low to the ground.
Pinpoint your find with a pinpoint probe. The probe is a small device used in conjunction with your metal detector to help you more accurately lock onto the location of your find. Once you hear your metal detector beep, spend a few extra minutes to accurately pinpoint it. This will save you from missing a potentially great find, or even worse, damaging a find by scraping it with your trowel because you dug too close to it.
Search areas that have some history of civilization to them. Geographically speaking, New England is often a good choice because of its human history and development. In contrast, you wouldn't want to search a shopping mall parking lot that was built in the past five years on previously undeveloped land because the chance of finding rare coins would be incredibly slim.
Examine old maps when planning your treasure hunt. Old maps can be an invaluable resource for locating old trade routes, buildings, roads and other structures that may no longer exist but were used by coin-carrying humans.
Search where others don't, including out in public, under brush and off the usual paths. For example, historic monuments are good, but old houses are better. Public parks are good, but old Indian trails are better. Be willing to go where no one else has gone before if you want to find something no one else has found.
Approach your search in stages. If you are after rare, and therefore most likely old, coins, they usually are buried deeper in the ground. A time-consuming, but perhaps optimal approach is to search every area with multiple passes of your detector. Begin with a shallow pass to unearth any recent loose change that has made its way into the ground. Make a second pass that probes a little deeper in the hunt for older artifacts.
The size and weight of your metal detector matters. Its dimension determines the space you can cover in a certain amount of time with your hunting endeavor. The weight is equally important because it determines how much you are able or not able to carry during the process. If the design of your metal detector allows it, you can outfit it with a larger coil. Generally speaking, larger coils provide signal penetration that goes deeper into the ground, where rarer coins usually lie. When you are about to enter private property with your search, make sure to get permission from the property's owner.